For TFS administrators that are really keeping an eye on their environment, it may bubble up that there is a top-heavy amount of execution time in the QueryBuildQueue command. At first glance this may appear to be a problem with the TFS instance in terms of server load.
The QueryBuildQueue command is generated by TE and BuildNotificationâ€¦.when TFS queue a build, TE and BuildNotification it will query the status of the build about every 30 seconds. Naturally, this will result in a multitude of QueryBuildQueue commands being issued. When a query beings, TFS requires establishing a connection to the Build Agent, which results in a time lapse will the request is issued and the subseuquent response is listened for, during this lapse period within the request / response frame, threads are idle so the load is nothing to be concerned in terms of server load.
Rest easy, fickle TFS admins :)